In the technical field constituted by the production of satellite structures made of composite materials, it is essential to provide strict thermic control of the elements constituting the structure by equipping them with both cooling units and heaters distributed at appropriate locations on the assembly. In fact, it is known that, depending on their position in sunlight or in shade, the various parts of a satellite are subjected to extremely wide temperature variations which, despite the choice of appropriate materials, may result in spacial deformations which, even if minimal, may render inoperative observation and communication transmission devices. One known solution consists of gluing to the appropriate elements of the structure a heater mainly consisting of a heating resistor, such as a printed circuit mounted on a plastic strip. This technique can be combined with another known technique and used in aeronautics so as to ensure the deicing of the fuselage or wings of an aircraft. This other technique consists of placing a composite structure with current conducting fibers at the critical zones to be de-iced, as described in the document FR-A 2 356 336. The feeding of electric current needing to traverse the fibers is effected via the connection of wires to a metallic frame mounted at the edge of the critical zones which is kept in contact with the fibers, or to a metallic deposit which is produced by vaporization or electrolytic means at the extremities of the critical zones containing the fibers. Apart from the drawback of being complex to mount and dispose, these devices have one major defect as regards the electric contacts required between the fibers and the feed wires owing to the fragility of gluings of the electric link. Moreover, the excess thicknesses existing at the locations of the electric connections are detrimental to the aerodynamic profile of the wings and impede the correct placing of structures for shielding and protecting the leading edges against impacts and erosion.
By virtue of the document FR-A 2 578 377 in the name of the Applicant, there exists a de-icing device able to avoid these drawbacks, a device in which the conductive fibers are carbon fiber appearing in the form of at least one strip in which the fibers are orientated longitudinally, the strip being preimpregnated with resin and having at least one extremity being fixed in the shape of a deformable tubular element with a metallic meshwork ensuring the required electric link via contact with said strip and by welding or crimping such to the corresponding feed wire.
However, as regards the embodiment of elementary parts made of a composite material and intended to form the load bearing structure of a satellite which are needing to be equipped with a heater, it seems impossible to add a strip and tubular element such as is shown in the prior art to each part.
The document FR-A 2 339 314 also describes conductive heating very thin layers incorporating conductors parallel to the direction of the orientation of these layers. The documents FR-A 2 233 487 or FR-A 1 533 941 describe motor vehicles with heated windows or laminated panels equipped with incorporated resistance wires, but these production techniques clearly prove to be totally unsuitable for employment in a satellite load bearing structure.
At the current moment, the adding of a heater to a composite support requires the prior cleaning of said support at the same time as the preparation of the surface quality of the heater, followed by masking of the support receiving the heater and then spreading a coating of glue on the assembled elements. Finally, after polymerization of the glue, the gluing zones need to be demasked and cleaned before fixing the connection cables, for example with the aid of collars. This gluing needs to be effectedly fully and evenly, firstly to ensure a correct regular thermic contact with the support, and secondly so as to avoid the risks of tearing or hooking of the corners of the heater during its various handlings and avoid leaving any air bubbles caught under the heater and which would burst in space!
This production technique does nevertheless have a certain number of drawbacks. In addition, it requires the passage of each elementary part through at least two workshops or production zones, namely firstly to make the basic part according to either of the known methods, namely via filamentary winding, draping of strips, etc., and then of adding to it the heating element. These operations not covered by each of these techniques and dealt with by the same specialists are thus effected one after the other and thus they double the production time and risks of pollution, and thus require that constricting precautions be taken as regards cleanness.